khan himself sent another mission in 127 ##3 , again demanding tribute . it too was rejected . in 127 ##5 , the emperor ordered the yunnan government to secure the border ##lands in order to block an escape path for the song , and permitted a limited border war if pagan contested . pagan did contest but its army was driven back at the frontier by the mongol army in 127 ##7 – 78 . after a brief lu ##ll , ku ##bla ##i khan in 128 ##1 turned his attention to southeast asia , demanding tribute from pagan , the khmer empire , đ ##ai viet and champ ##a . when the burmese king again refused , the emperor ordered an invasion of northern burma .
khan himself sent another mission in 1273, again demanding tribute. it too was rejected. in 1275, the emperor ordered the yunnan government to secure the borderlands in order to block an escape path for the song, and permitted a limited border war if pagan contested. pagan did contest but its army was driven back at the frontier by the mongol army in 1277 – 78. after a brief lull, kublai khan in 1281 turned his attention to southeast asia, demanding tribute from pagan, the khmer empire, đai viet and champa. when the burmese king again refused, the emperor ordered an invasion of northern burma.